BYU (24-11) went on an 11-0 run early in the first half and never trailed again, leading by double digits the entire second half. Zylstra drilled five 3-pointers in the first half and the Cougars shot 11 of 27 (40.7 percent) from long range.

Brandon Davies added 12 points and 13 rebounds.

Southern Miss (27-10) lost at home for just the second time in two seasons. Daveon Boardingham led the Golden Eagles with 18 points and Jerrold Brooks added 13.

The Cougars will next face either Providence or Baylor in the semifinals of the NIT at Madison Square Garden in New York.